FRONTLINE spent months reporting for the documentary Putin’s Revenge, speaking with the heads of U.S. intelligence agencies, diplomats, journalists, scholars and political insiders from Russia and the United States. In all, 56 sources spoke to us on camera. Now, in an effort to make our journalism more transparent, we’re publishing the complete collection of these extended conversations. In “The Putin Files,” explore the interviews using interactive features that enable you to navigate by theme or person, select and share any excerpt on social media, and dig deeper into annotated content about this still unfolding history.